From www.psychologicalscience.org - January 5, 2012 5:32 AM

What we do know is that measures of general intelligence are practically useful. Frank Schmidt, of the University of Iowa, and the late John Hunter, of Michigan State University, documented that g is the single best predictor of job performance across a wide range of occupations — better than personality, interest, motivation and even job experience. People who do well on tests of intelligence tend to make the best mechanics, managers, clerks, salespeople, pilots, detectives and scientists. They also tend to make the best teachers. It makes perfectly good sense, as Andrew Biggs and Jason Richwine argue, to use intelligence as a predictor of teacher performance. We should want smart people to be our teachers.